Description
In recent years, shape memory alloys (SMAs) have been widely employed for a variety of structural purposes. Among different types of SMAs, iron-based SMAs (Fe-SMAs) have been recently used as reinforcement for concrete structures because of their distinct mechanical properties and lower production costs. In such applications, the pre-strained Fe-SMAs must first be activated in order to apply the necessary pre-stress to the structure. The process of activating Fe-SMAs in concrete involves three main physical steps, including the generation of heat in the SMA through the passage of an electric current, the transfer of heat from the SMA to the concrete, and the creation of pre-stress in the specimen. In the present study, the activation process of a Fe-SMA-reinforced concrete beam is simulated through multiphysics modelling with Comsol software. For Fe-SMA reinforcements, two different geometries—bar and strip—are taken into consideration. For these two kinds of specimens, comparisons are made on the temperature and stress distribution results. Initially, the model is verified with the available experimental data. Afterwards, using a parametric study, the results are examined for the impact of geometrical parameters and activation parameters, such as applied voltage and activation time. The presented modelling technique can enhance the use of Fe-SMAs in a variety of engineering domains, particularly civil engineering fore reinforcement of concrete specimens.
